单选题：回答题：　　The bizarre antics of sleepwalkers havepuzzled police,

回答题：
　　The bizarre antics of sleepwalkers havepuzzled police, perplexed scientists, and fascinated writers for centuries.There is an endless supply of stories about sleepwalkers. Persons have beensaid to climb on steep roofs, solve mathematical problems, compose music, walkthough plate glass windows, and commit murder in their sleep.
　　How many of these stories have a basic infact, and how many are pure fakery? No one knows, but if some of the mostsensational stories should be taken with a barrel of salt, others are a matterof record．
　　There is an early medical record of asomnambulist who wrote a novel in his sleep. And the great French writerVoltaire knew a sleepwalker who once got out of bed, dressed himself, made apolite bow, danced a minuet, and then undressed and went back to bed．
　　At the University of Iowa, a student wasreported to have the habit of getting up in the middle of the night and walkingthree-quarters of a mile to the Iowa River. He would take a swim and then goback to his room to bed．
　　The world's champion sleepwalker wassupposed to have been an Indian, who walked sixteen miles along a dangerousroad without realizing that he had left his beD．Second in line for the titleis probably either a Vienna housewife or a British farmer. The woman did allher shopping on busy streets in her sleep. The farmer, in his sleep, visited aveterinarian miles away.
　　The leading expert on sleep in Americanclaims that he had never seen a sleepwalker. He is Dr. Nathaniel Kleitman, aphysiologist at the University of Chicago. He is said to know more about sleepthan any other living man, and during the last thirty-five years had lost a lotof sleep watching people sleep. Says he, "Of course, I know that there aresleepwalkers because I have read about them in the newspapers. But none of mysleepwalkers ever walked, and if I were to advertise for sleepwalkers for anexperiment, I doubt that I'd get many takers."
　　Sleepwalking, nevertheless, is ascientific reality. Like hypnosis, it is one of those dramatic, eerie,awe--inspiring phenomena that sometimes border on the fantastiC．It lendsitself to controversy and misconceptions. What is certain about sleepwalking isthat it is a symptom of emotional disturbance, and that the only way to cure itis to remove the worries and anxieties that cause it. Doctors say thatsomnambulism is much more common than is generally supposeD．Some have set estimatedthat there are four million somnambulists in the United States. Others set thefigure even higher. Many sleepwalkers do not seek help and so are never put onrecord, which means that an accurate count can never be made.
　　The simplest explanation of sleepwalkingis that it is the acting out of vivid dream. The dream usually comes fromguilt, worry, nervousness, or some other emotional conflict.
　　The age-old question is: Is thesleepwalker actually awake or asleep? Scientists have decided that he is abouthalf-and-half. Dr. Zelda Teplitz, who made a ten-year study of the subject,say, "Some people stay awake all night worrying about their problems. Thesleepwalker thrashes them out in his sleep. He is awake in the muscular area,partially asleep in the sensory areA．" In other words, a person can walkin his sleep, move around, and do other things, but he does not think aboutwhat he is doing.
　　There are many myths about sleepwalkers.One of the most common is the idea that it's dangerous or even fatal to waken asleepwalker abruptly. Experts say that the shock suffered by a sleepwalkersuddenly awakened is no greater than that suffered in waking up to the noise ofan alarm clock. Another mistaken belief is that sleepwalkers are immune to injury.Actually most sleepwalkers trip over rugs or bump their heads on doors at sometime or other.
　　What are the chances of a sleepwalkercommitting a murder or doing something else extraordinary in his sleep? Somecases of this have been reported, but they very rarely happen. Of course thefew cases that are reported receive a great deal of publicity. Dr. Teplitzsays, "Most people have such great inhibitions against murder or violencethat they would awaken-if someone didn't waken them." In general,authorities on sleepwalking agree with her. They think that people will not doanything in their sleep that is against their own moral code.
　　Parents often explain their children's-ortheir own-nocturnal oddities as sleepwalking. Sleepwalking is used as an excusefor all kinds of irrational behavior. There is a case on record of a woman whodreamed that her house was on fire and flung her baby out of the window. Dr.Teplitz believes that this instance of irrational behavior was not due tosomnambulism. She believes the woman was seriously deranged or insane, not asleepwalker.
　　For their own protection, chronicsleepwalkers have been known to tie themselves in bed, lock their doors, hidethe keys, bolt the windows, and rip up all sorts of gadgets or wake themselvesif they should get out of beD．Curiously enough, they have an uncanny way ofavoiding their own traps when they sleepwalk, so none of their tricks seem towork very well. Some sleepwalkers talk in their sleep loudly enough to wakesomeone else in the family who can then shake them back to their senses.
　　Children who walk in their sleep usuallyoutgrow the habit. In many adults, too, the condition is more or less temporary.If it happens often, however, the sleepwalker should seek　help.　Althoughsleepwalking itself is nothing to become alarmed about, the problems that causethe sleepwalking may be very serious.
Whatdoes the phrase "taken with a barrel of salt" at the end of thesecond paragraph mean? A．inconceivable
B．unbelievable
C．suspected
D．implausible